long shot - anyone applied for SA citizenship from UK?

I am I think entitled to claim SA citizenship by descent, which I am going to do in advance of a move out there next year - lots of benefits obviously not least that I can work (we will be going on DP's work visa otherwise).

It is all a bit confusing - I have to start off with a Late Registration of Birth - but I can't work out really simple things like where I send the forms too . It would be lovely (but unlikely!) if someone else has recently gone through the process...